This invention relates to 4-cyclooctenyl alkyl carbonates defined according to the structure: ##STR2## wherein R.sub.4 is methyl or ethyl and mixtures containing high proportions of said 4-cyclooctenyl alkyl carbonates and minor proportions of bicyclooctanyl carbonates having the structure: ##STR3## wherein R.sub.5 is methyl or ethyl and uses of such mixtures and said 4-cyclooctenyl alkyl carbonate in augmenting or enhancing the aroma of perfume compositions, colognes and perfumed articles.
Materials which can provide minty, strawberry-like, herbal, sweet, intense violet-like, green, cucumber-like, pear-like and banana-like aroma nuances with tagette-like and birch tar-like undertones are highly desirable in the art of perfumery. Many of the natural substances which provide such fragrance nuances and contribute the desired nuances to perfumery compositions are high in cost, vary in quality from one batch to another and/or are generally subject to the usual variations of natural products.
The prior art contains a large number of teachings regarding the use of organic carbonates in augmenting or enhancing the aroma of perfumes. Thus, U.S. Pat. No. 4,033,993 discloses the use of organic carbonates defined according to the structure: ##STR4## wherein R.sub.1 is a moiety having from 8 to 12 carbon atoms selected from the group consisting of alkylcyclohexyl, alkenylcyclohexyl, alkynylcyclohexyl and cycloalkyl and R.sub.2 is a moiety selected from the group consisting of alkyl having from 1 to 5 carbon atoms, alkenyl having from 2 to 5 carbon atoms and alkynyl having from 2 to 5 carbon atoms. U.S. Pat. No. 4,033,993 describes, for example, methyl-1-ethynycyclohexyl carbonate having a fruity, herbal complex odor and distinct fragrance of dill. In addition, U.S. Pat. No. 4,033,993 describes methyl cyclooctyl carbonate as having an herbal, natural and complex fragrance which is distinguished by a strong and long clinging flowery jasmine scent and further indicates its use in jasmine perfume compositions. U.S. Pat. No. 4,033,993 describes the preparation of the compounds defined according to the structure: ##STR5## according to the reaction: ##STR6## wherein R.sub.1 and R.sub.2 are defined as above.
In addition, U.S. Pat. No. 4,080,309 describes the perfume use of the carbonates defined according to the structure: ##STR7## wherein R.sub.1 ' is a moiety having from 8 to 12 carbon atoms selected from the group consisting of alkylcyclohexyl, alkenylcyclohexyl, alkynylcyclohexyl and cycloalkyl and R.sub.2 ' is a moiety selected from the group consisting of alkyl having from 1 to 5 carbon atoms, alkenyl having from 2 to 5 carbon atoms and alkynyl having from 2 to 5 carbon atoms. Described in U.S. Pat. No. 4,080,309 are also such compounds as methyl cyclooctyl carbonate and the use thereof in jasmine perfume formulations. As is the case in U.S. Pat. No. 4,033,993, the carbonates of 4,080,309 are indicated to be prepared according to the reaction: ##STR8##
4-Cyclooctenyl formate having the structure: ##STR9## a precursor of the 4-cyclooctenyl alkyl carbonates of our invention, is indicated to be produced by reaction of 1,5-cyclooctadiene with formic acid in German Offenlegungsschrift No. 3,037,093 published on Nov. 12, 1981, the specification for which is incorporated by reference herein. Said German Offenlegungsschrift is abstracted in Chem. Abstracts, Volume 96, 68448q.
Nothing in the prior art, however, discloses the 4-cyclooctenyl alkyl carbonates of our invention and nothing discloses such 4-cyclooctenyl alkyl carbonates as having the specific fragrance nuances and fragrance utilities as set forth infra.